title: Urinary biomarkers of oxidative/nitrosative stress in healthy smokers.
abstract: OBJECTIVE
  To evaluate the effect of cigarette smoking on oxidative and nitrosative stress, we assessed urinary levels of 8-hydroxy-2'-deoxyguanosine (8-OHdG), isoprostane 15-F(2t)-IsoP, thiobarbituric acid-reacting substances (TBARS), advanced glycation end-products (AGEs), dityrosine (diTyr), hydrogen peroxide, total nitrite and nitrate and trolox equivalent antioxidant capacity (TEAC) in healthy smokers.
  
  
  METHODS
  Fluorimetric and spectrophotometric assays were performed in urine samples of 33 healthy smokers and 58 age-matched controls.
  
  
  RESULTS
  Levels of 8-OHdG, 15-F(2t)-IsoP and AGES were found significantly higher in smokers than in controls (10.7 ng/mg Cr vs. 8.3 ng/mg Cr, 1.41 ng/mg Cr vs. 1.01 ng/mg Cr and 189 AFU/mg Cr vs. 143 AFU/mg Cr, respectively; P < 0.05 for all). Positive correlations were found between age and levels of AGEs and diTyr in smokers (r = 0.380, P < 0.035 and r = 0.418, P < 0.019, respectively) and also between age and AGEs, diTyr and TEAC in controls (r = 0.474, P < 0.001, r = 0.463, P < 0.001 and r = 0.576, P < 0.001, respectively), being this correlation negative for 8-OHdG in controls (r = -0.295, P = 0.041). Positive correlation between the number of cigarettes smoked per day and AGEs was also found (r = 0.355, P = 0.044).
  
  
  CONCLUSIONS
  Urinary 8-OHdG, 15-F(2t)-IsoP and AGEs may represent a non-invasive quantitative index of oxidant stress in healthy smokers, being AGEs a possible indicator of tobacco toxin exposure. The increased oxidative stress in healthy smokers observed may be generated because of an excessive production of reactive oxygen species and not by exhaustion of antioxidant defenses.
authors.affiliation: Department of Cellular and Molecular Medicine, Centre for Biological Research-Spanish National Research Council (CIB-CSIC), Madrid, Spain. ccampos@cib.csic.es
authors.forename: Carlos
authors.initials: C
authors.lastname: Campos
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Guzmán
authors.forename: Encarnación
authors.initials: E
authors.lastname: López-Fernández
authors.forename: Ángela
authors.initials: Á
authors.lastname: Casado
mesh_terms: D000080242:8-Hydroxy-2'-Deoxyguanosine; D000328:Adult; D000375:Aging; D000975:Antioxidants / Q000032:analysis; D015415:Biomarkers / Q000652:urine; D004249:DNA Damage; D003849:Deoxyguanosine / Q000031:analogs & derivatives / Q000652:urine; D015237:Dinoprost / Q000031:analogs & derivatives / Q000652:urine; D005260:Female; D017127:Glycation End Products, Advanced / Q000652:urine; D006801:Humans; D015227:Lipid Peroxidation; D008297:Male; D008875:Middle Aged; D018384:Oxidative Stress; D026361:Reactive Nitrogen Species / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000378:metabolism*; D012907:Smoking / Q000009:adverse effects / Q000378:metabolism / Q000652:urine*; D055815:Young Adult
chemical_list: D000975:Antioxidants; D015415:Biomarkers; D017127:Glycation End Products, Advanced; D026361:Reactive Nitrogen Species; D017382:Reactive Oxygen Species; C075750:8-epi-prostaglandin F2alpha; D000080242:8-Hydroxy-2'-Deoxyguanosine; D015237:Dinoprost; D003849:Deoxyguanosine